diff --git a/pkgs/development/python-modules/contextlib2/default.nix b/pkgs/development/python-modules/contextlib2/default.nix
index cadaa8914b21..a056ba450a88 100644
--- a/pkgs/development/python-modules/contextlib2/default.nix
+++ b/pkgs/development/python-modules/contextlib2/default.nix
@@ -1,6 +1,7 @@
 { lib
 , buildPythonPackage
 , fetchPypi
+, unittest2
 }:
 
 buildPythonPackage rec {
@@ -13,9 +14,11 @@ buildPythonPackage rec {
     sha256 = "509f9419ee91cdd00ba34443217d5ca51f5a364a404e1dce9e8979cea969ca48";
   };
 
+  checkInputs = [ unittest2 ];
+
   meta = {
     description = "Backports and enhancements for the contextlib module";
     homepage = http://contextlib2.readthedocs.org/;
     license = lib.licenses.psfl;
   };
-}
\ No newline at end of file
+}